An NMR MULTIFID method for measurement of magnetic field gradient

The described MULTIFID method, that allows measurement of the time characteristic of the magnetic field gradient G_z(t), is based on the measurement of the instantaneous frequency of FID signals periodically recorded immediately after switching off the gradient pulse. The method was used for a fast and sufficiently accurate determination of the pre-emphasis time and amplitude constants. The preemphasis filter used allows one to shorten the decay time of the gradient magnetic field G_z from 200 ms to 100 mu s, and, thereby, to carry out a good compensation for the influence of eddy currents for the purposes of NMR spectroscopy and microscopy.